1. Field of the Invention
This invention relates to improvements in apparatus for closing cases or cartons, and more particularly relates to an apparatus for automatically closing a top flap of an L-slide lock case.
2. Description of Background Art
The art of closing corrugated cardboard cases or cartons is old and well worked. It is known, for example, to move such cartons on a conveyor past stationary cams or the like for various operations of sealing and folding flaps. See, for example, U.S. Pat. Nos. 2,277,289, 2,261,767, 2,270,264.
Cartons having L-slide locks are commercially available from Stone Container Corp. and are widely used in the industry. Such cartons or cases are used by Frito-Lay, Inc. (the assignee of this application) to package bags of snack foods such as potato chips, corn chips, and the like, for shipment. The L-slide locks on the cartons make them easy to close by just inserting the opposite ends of an upstanding flap into the lock slots. L-slide lock cases are advantageous for shipment of snack food bags and the like because they are re-usable and can be closed without the use of glue, staples, tape, or other destructive closure means. When the cases are emptied, they are collapsible as set forth in U.S. Pat. Nos. 3,960,313 and 4,007,869, for ease in shipment back to the factory to be refilled. Prior to the present invention, the L-slide lock cases were manually closed after the bags of product were packed into the case. The obvious drawbacks to manual closing are that it is a labor-intensive, time-consuming and hence extremely expensive.
There is need in the art for an automatic case closing apparatus for L-slide lock cartons. This need has existed for some time until the present invention.